TNUCKL

Hey all....new here and new to owning a JEEP!!!

I've got a 95 V6 Laredo with Quadra Trac alltime drive.

My question is this. I can put either the left or right front wheel on patch of ice with the other three tires on solid ground and the wheel on the patch of ice just spins when I punch it and the ride doesn't move. But give me 8 inches of snow and the beast powers through it like a tank. What gives? Haven't tried the back wheels on ice patch yet.

I would think the three wheels on dry pavement would kick in to compensate for the spinning tire on the ice.

Thanks in advance..great site.
Thomas

Bustedback

I hope you mean I6. If all four wheels have equal traction the vehicle will move. But when you have three wheels with traction and punch it, the power will go to the wheel with the least resistance. If you ease into the throttle, instead of punching it, power will be sent equally to all of the wheels. Sometimes slightly applying the brakes will help by giving the wheel with no traction some resistance and power will be sent to the other wheels.

TNUCKL

Yes I6

So your saying that if I have 3 good wheels out of 4 the system fails me?

Bustedback

Yep, unless you have lockers in the diffs.

jnicewan

Quadratrac and any other AWD selected t-case can do this. Think about how an open diff works (one tire spin) Now since the t-case is all time there is a differential in there too or some type of coupling that allows slippage. The 249 uses a viscous coupler so its acts more like a loose posi. The power split on these systems can be variable.

So its possible that if you have a 4wd/awd it may only spin one tire on one axle with all the others stationary. Any part time t-case or lockable awd (4H or 4H lock) will have to at least spin one tire on each axle, the t-case is locked meaning 100% of the power is split to the frt and rear axle.

jnicewan

Lockers in the diffs would still allow one axle to be stationary while the other axle spins but both tires on that axle would have to be able to spin.

TNUCKL

Still sounds flawed to me...on board computer should be programed to detect the other wheels aren't moving and at that point making the assumption that the car isn't moving and therefore start to put power to the other wheels. I'm getting how it works/thinks, but it just don't seem right to be stuck with 3 tires firmly planted.

Nick-B

That would take a very complex computer and traction control system - something our old rigs simply did not have the ability to do.
I hate to say it but the only maker I've seen that is doing what you describe is Subaru. This video shows it pretty good.
#/watch?feature=related&v=t09ExAUgtyE

TNUCKL

That is very interesting...thanks for the post. The guy I purchased my ride from stated that the Quadra trac would pull/push you out if 3 wheels were on ice and one planted on firm ground. Much like the Subaru did with 3 wheels spinning. Wish they would have shown my scenario with one wheel spinning in the front with traction to the other three wheels.

jnicewan

Well the good old trusty part time 4wd systems are much cheaper, less parts involved, does not require any electronics, and this issue above can not happen with a part time 4wd.

Jeep had 3 different systems back in 95 and you have the worst one for situations like these, unfortunately the system works best when traction is similar for all 4 tires. Get a NP 231 or at least an NP 242 if it bothers you that bad. Keep in mind an NP242 can do that too in all time 4H, but you can shift it to part time, shifting the 242 to part time is just like locking a selectable locker except the diff is in the trans and the axles are the driveshaft outputs.

dave1123

Okay, explain to me why I passed with ease, a 2012 Subaru Forester slipping and sliding on 4" of snow with black ice underneath in my WJ in full time 4WD. I put it down to a newbie driver and stock tires. How do I know it was a 2012, you ask? Because this was last winter and he still had the production sticker in the window with his own plates.

I thought the intelligent system was supposed to compensate for inexperienced drivers. Apparantly not.

BTW, I have the 242 t-case.

TNUCKL

I think a lot of this is meant for the basic driver while in motion. Moving power to wheels and compensating in every way its designed to do, but from dead stops...the systems are really limited until a lock is applied to a differential. Mine powers through snow no problem, but at dead stop with a wheel on ice-it don't move. Wheel on ice just spins. I suspect if I was crawling and one wheel got stuck in the air--the Quadra-trac system would just spin the wheel in the air and the ride wouldn't move. YES?

dave1123

Yes. That's the way my 242 acts in full time. Part time locks out the diff in the t-case.